Providers of telephone answering services accept calls directed to their customers by others. In many instances, the service is provided by bridges to TAS customers' lines at the nearest telephone company (TELCO) switching centre that are extended to appear at an operator position at the TAS premises. Incoming calls to customers ring also at the TAS operator position. The customer telephones the TAS operator with instructions to commence or cease answering.
Depending on the traffic pattern of customer calls, an operator position may be required to handle up to 100 customers. As a TAS office normally has several operator positions, it is necessary to place these positions in proximity, on order that a vacant position be answered by a neigbouring operator. Otherwise concentrators and call distributors would be necessary.
A typical modern system called AUTOTAS.TM. is sold by Candela Electronics, Inc. of Sunnyvale, Calif., U.S.A. This system may handle up to 1000 customers by concentrating them into 29 trunks that are then distributed to 6 operator positions. The system is centralized, microprocessor controlled, and has several desirable features for the TAS bureaus.
U.S. Pat. No. 4,328,396 granted to Peter F. Theis on May 4, 1982, provides a telephone answering system including answering machines, for carrying on a programmed telephone conversation with a respondent, having an interface with the telephone line, and a control for altering the course of the programmed conversation when a disconnect signal is passed by the interface. The system contemplates serving a multiplicity of incoming telephone calls with a number of line operator stations, with the capability of overflow calls being handled by the answering machines. The system also includes a concentrator which continuously sweeps the incoming telephones lines to select any line having an unanswered call, continuously sweeps the answering machines to identify an available machine, and then effects a connection between the selected telephone line and the available machine.
U.S. Pat. No. 4,302,632 granted to Ronald P. Vicari et al on Nov. 24, 1981 provides a digitally controlled telephone answering switching system, which is capable of serving a large number of subscribers over a vast geographic area. The system utilizes a plurality of remote sites each of which is adjacent to a telephone company central office and which includes a trunk concentrator to reduce the number of trunk lines required to service the subscribers. A central site of this answering system serves as a facility to answer calls relayed through the remote sites. It includes a concentrator to further reduce the number of lines to operator positions. A computer at the central site controls the entire system, determines switching paths through the concentrators from a subscriber line to an operator, furnishes answering information to operators and stores instructions for answering incoming messages. The logic of the system permits any operator to answer any incoming telephone call on any subscriber line promptly, economically and correctly.
In addition, U.S. Pat. No. 4,200,772 also granted to Ronald P. Vicari et al on Apr. 29, 1980, provides in the system a line scanner which counts rings on an incoming line to determine whether it should be answered, and an arrangement in the control computer for controlling coupling of a signal on a line to be answered to a selected operator position having a visual display, to which is transmitted data relative to the subscriber associated with a call to be answered by the selected operator position.
In an earlier U.S. Pat. No. 3,637,947 granted to Charles Breen on Jan. 25, 1972, telephone answering service is provided by modifying a central office (switching centre) at the telephone company by the addition of an auxilliary switching network upon which are terminated telephone answering board incoming trunks and call forwarding trunks. These trunks also appear at respective remote telephone answering switchboards and each has a line circuit appearance in the main switching network. The system is arranged so that an incoming connection via a telephone answering board incoming trunk may be extended to a remote destination via a selected call forwarding trunk under control of the telephone answering board. A controller circuit associated with the auxilliary switching network is responsive to control signals from the remote telephone answering switchboard to enable a connection between the activated telephone answering board incoming trunk and the selected call forwarding trunk via the auxilliary switching network located at the central office.
Common among all of the above systems are two main features:
auxilliary switching or concentration, in addition to telephone company facilities; and PA1 central control of the total system.
In essence, a parallel, centralized telephone switching system is created for each TAS bureau.